Configuring The Port Cost - Cisco nexus 5000 series Cli Configuration Manual

Chapter 1 Configuring MST
S e n d f e e d b a c k t o n x 5 0 0 0 - d o c f e e d b a c k @ c i s c o . c o m
Command
Step 2
switch(config)# interface {{type
slot/port} | {port-channel number}}
Step 3
switch(config-if)# spanning-tree mst
instance-id port-priority priority
This example shows how to set the MST interface port priority for MSTI 3 on Ethernet port 3/1 to 64:
switch# configure terminal
switch(config)# interface ethernet 3/1
switch(config-if)# spanning-tree mst 3 port-priority 64
You can only apply this command to a physical Ethernet interface.

Configuring the Port Cost

The MST path cost default value is derived from the media speed of an interface. If a loop occurs, MST
uses the cost when selecting an interface to put in the forwarding state. You can assign lower cost values
to interfaces that you want selected first and higher cost to interfaces values that you want selected last.
If all interfaces have the same cost value, MST puts the interface with the lowest interface number in the
forwarding state and blocks the other interfaces.
MST uses the long pathcost calculation method.
Note
To configure the port cost, perform this task:
Command
Step 1
switch# configure terminal
OL-16597-01
Purpose
Specifies an interface to configure, and enters
interface configuration mode.
Configures the port priority as follows:
For instance-id, you can specify a single MSTI, a
•
range of MSTIs separated by a hyphen, or a series
of MSTIs separated by a comma. The range is
from 1 to 4094.
For priority, the range is 0 to 224 in increments of
•
32. The default is 128. A lower number indicates
a higher priority.
The priority values are 0, 32, 64, 96, 128, 160, 192,
and 224. The system rejects all other values.
Purpose
Enters configuration mode.
Cisco Nexus 5000 Series Switch CLI Software Configuration Guide
Configuring MST
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